The video was shot by filmmaker Andrew David Watson and appears on Etsy, the arts & crafts website, as part of its documentary series.

"It's not open to the public as such. It's not legal so that's why it has to be hidden," he continues, speaking to the camera as he smokes a pipe surrounded by shelves of old books.

Seidenberg said people often ask for his card — but he doesn't print any.

"I'm a secret bookstore. It would be ridiculous to have a card," he said.

He is, however, in the phone book. DNAinfo reached Seidenberg that way, as have many other people, apparently, after seeing the Etsy video.

"I've had a lot of phone calls and messages and people friending me on Facebook," Seidenberg said.

He knows the attention might attract the authorities, saying, "I'll just deal with it when I have to deal with it."

He does, after all, want people to find him.

"I've been written about a lot," Seidenberg said. But a New Yorker "Talk of the Town" piece, which ran in 2008 when his secret store first opened, kept the location very discreet.

"That was kept so secret it never affected anything. After a while, people thought it was an urban myth created by writers."

Seidenberg had turned down requests for interviews by the New York Times and Wall Street Journal, but said yes to the Etsy video, thinking it would only be seen by people "wanting to buy potholders."

"I guess I did 100 percent underestimate the Internet," he said.

Seidenberg, who counted author Jonathan Lethem among his employees, moved Brazenhead from Brooklyn to his Manhattan shop. When that shop closed 15 years ago, he sold at book fairs or on the street, which he did not enjoy.

The real estate prices that forced him out also prevented him from finding a new space, but he didn't want to give up selling used books like the shops on 14th Street he remembered from his youth.

"This wasn't what I had planned," he said. "But it's perfect for me."

He's enjoyed meeting every person who has come to his store, which he runs in his former apartment, he said.

Seidenberg doesn't want people to be scared of the appointment-only one-on-one attention; he doesn't mind if he sits with someone for three hours and only sells them a $4 book. But since he worries that other people might feel uncomfortable with the set-up, Seidenberg holds salons on Saturday where people who call for the unlisted address can come any time.

He also often hosts classes from Columbia and New York University in his shop.

Watson, who cut his footage down from an hour of tape, said in a blog post that he hoped the shop remained "one of those special, hidden delights New York City has to offer."

He also left with a bigger lesson: "I think the most important thing I learned from Michael is how rewarding it is to live your life by your own terms."

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